Semi-Automation Of A Non-Radioactive Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) Assay (Part I)

We describe the use of a non-radioactive, bioluminescent Antibody-Dependent Cell- Mediated Cytotoxicity (ADCC) assay. The protocol is a simple sequential addition of reagents and cells that can be readily automated with a simple, inexpensive pipetting station. Here we demonstrate the semi-automation of the ADCC assay using Daudi cells, rituximab (monoclonal antibody used in the drug Rituxan) and freshly isolated primary human NK cells.

Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC) is part of a host immune defense where an effector cell of the immune system is directed to lyse a target cell or pathogen. This is accomplished by specific antibodies raised against antigens on the target cell/pathogen surface. It is one of the mechanisms through which antibodies act to limit and contain infection. One of the most common effector cell types is natural killer (NK) cells. Antibodies recruit effector cells such as NK cells through their Fc portion. NK cells, for example, express CD16 or FcγRIII (CD16a) on their cell surface, which are Fc receptors that recognize the Fc portion of an antibody, such as IgG. Thus once the antibody binds to the target cell, it can bring NK cells in close proximity to the target cell through binding of its Fc receptors to the Fc portion of the IgG. Once this binding event occurs, the NK cell releases cytokines and cytotoxic granules that enter the target cell and promote apoptosis.